The encoding of the ecCodes paramId, shortName, name and units have changed for some surface parameters from the analysis and forecast. Users may need to adapt their workflows in order to process these parameters successfully. The main changes affecting parameters provided in the static sample dataset are summarised below. For a list of all changes to parameter encoding made at each ecCodes version, see Migration to GRIB2 - new in ecCodes.
Soil temperature, volumetric soil moisture and sea-ice temperature
In GRIB1, soil temperature, volumetric soil moisture and sea-ice temperature have different paramIds for each of the 4 soil layers. In GRIB2, only a single paramId is used with the layer indicated by the level key.
For example, in GRIB1, there is a paramId for Volumetric soil water layer 1 and a different paramId for Volumetric soil water layer 2, etc. In GRIB2, only a single paramId is used for Volumetric soil water, with the layer 1 having level=1 and layer 2 having level=2.
| Old paramId | Old shortName | Old name | Old units | New paramId | New shortName | New name | New units | level |
|---|---|---|---|---|---|---|---|---|
| 139 | stl1 | Soil temperature level 1 | K | 260360 | sot | Soil temperature | K | 1 |
| 170 | stl2 | Soil temperature level 2 | K | 260360 | sot | Soil temperature | K | 2 |
| 183 | stl3 | Soil temperature level 3 | K | 260360 | sot | Soil temperature | K | 3 |
| 236 | stl4 | Soil temperature level 4 | K | 260360 | sot | Soil temperature | K | 4 |
| 39 | swvl1 | Volumetric soil water layer 1 | m**3 m**-3 | 260199 | vsw | Volumetric soil moisture | m**3 m**-3 | 1 |
| 40 | swvl2 | Volumetric soil water layer 2 | m**3 m**-3 | 260199 | vsw | Volumetric soil moisture | m**3 m**-3 | 2 |
| 41 | swvl3 | Volumetric soil water layer 3 | m**3 m**-3 | 260199 | vsw | Volumetric soil moisture | m**3 m**-3 | 3 |
| 42 | swvl4 | Volumetric soil water layer 4 | m**3 m**-3 | 260199 | vsw | Volumetric soil moisture | m**3 m**-3 | 4 |
| 35 | istl1 | Ice temperature layer 1 | K | 262024 | sit | Sea ice temperature | K | 1 |
| 36 | istl2 | Ice temperature layer 2 | K | 262024 | sit | Sea ice temperature | K | 2 |
| 37 | istl3 | Ice temperature layer 3 | K | 262024 | sit | Sea ice temperature | K | 3 |
| 38 | istl4 | Ice temperature layer 4 | K | 262024 | sit | Sea ice temperature | K | 4 |
These parameters will be archived in MARS with levtype=sol (surface other levels). To retrieve these parameters in GRIB2, users will need to change their MARS requests to specify levtype=sol,levelist=1/2/3/4.
Parameters statistically processed over a time window
In GRIB1, parameters that are statistically processed over a time window, such and maximum, minimum and average values over the last 3 or 6 hours, have different paramIds for each time window available. In GRIB2, there is a unique paramId indicating the parameter and type of statistical processing, e.g., paramId=237167, shortName=max_2t for maximum temperature at 2 metres. A separate key, called statisticalwindow, is then used to specify the time window. For example, paramId=237167, statisticalwindow=3h identifies maximum temperature at 2 metres during the last 3 hours.
This change applies to:
- Maximum 10 metre wind gust.
- Maximum and minimum temperature at 2 metres.
- Maximum and minimum total precipitation rate.
- Maximum CAPE and CAPE shear.
- Average lightning flash density.
- Most severe and most frequent precipitation type.
To retrieve these parameters in GRIB2 from MARS, users will need to use the new paramId and also specify the statistical processing time window using a new MARS keyword - timespan - that is to be introduced.
Maximum 10m wind gust
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | New ParamId | New shortName | name | units | timespan | stepType |
|---|---|---|---|---|---|---|---|---|
| 49 | 10fg | Maximum 10 metre wind gust since previous post-processing | 237318 | max_i10fg | Time-maximum 10 metre wind gust | m s**-1 | 1h/3h/6h | max |
| 228028 | 10fg3 | Maximum 10 metre wind gust in the last 3 hours | 237318 | max_i10fg | Time-maximum 10 metre wind gust | m s**-1 | 3h | max |
| 123 | 10fg6 | Maximum 10 metre wind gust in the last 6 hours | 237318 | max_i10fg | Time-maximum 10 metre wind gust | m s**-1 | 6h | max |
Maximum and minimum 2m temperature
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | New ParamId | New shortName | name | units | timespan | stepType |
|---|---|---|---|---|---|---|---|---|
| 201 | mx2t | Maximum temperature at 2 metres since previous post-processing | 237167 | max_2t | Time-maximum 2 metre temperature | K | 1h/3h/6h | max |
| 202 | mn2t | Minimum temperature at 2 metres since previous post-processing | 238167 | min_2t | Time-minimum 2 metre temperature | K | 1h/3h/6h | min |
| 228026 | mx2t3 | Maximum temperature at 2 metres in the last 3 hours | 237167 | max_2t | Time-maximum 2 metre temperature | K | 3h | max |
| 228027 | mn2t3 | Minimum temperature at 2 metres in the last 3 hours | 238167 | min_2t | Time-minimum 2 metre temperature | K | 3h | min |
| 121 | mx2t6 | Maximum temperature at 2 metres in the last 6 hours | 237167 | max_2t | Time-maximum 2 metre temperature | K | 6h | max |
| 122 | mn2t6 | Minimum temperature at 2 metres in the last 6 hours | 238167 | min_2t | Time-minimum 2 metre temperature | K | 6h | min |
Maximum and minimum total precipitation rate
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | Old units | New paramId | New shortName | New name | New units | timespan | stepType |
|---|---|---|---|---|---|---|---|---|---|
| 228226 | mxtpr | Maximum total precipitation rate since previous post-processing | kg m**-2 s**-1 | 237055 | max_tprate | Time-maximum total precipitation rate | kg m**-2 s**-1 | 1h/3h/6h | max |
| 228227 | mntpr | Minimum total precipitation rate since previous post-processing | kg m**-2 s**-1 | 238055 | min_tprate | Time-minimum total precipitation rate | kg m**-2 s**-1 | 1h/3h/6h | min |
| 228222 | mxtpr3 | Maximum total precipitation rate in the last 3 hours | kg m**-2 s**-1 | 237055 | max_tprate | Time-maximum total precipitation rate | kg m**-2 s**-1 | 3h | max |
| 228223 | mntpr3 | Minimum total precipitation rate in the last 3 hours | kg m**-2 s**-1 | 238055 | min_tprate | Time-minimum total precipitation rate | kg m**-2 s**-1 | 3h | min |
| 228224 | mxtpr6 | Maximum total precipitation rate in the last 6 hours | kg m**-2 s**-1 | 237055 | max_tprate | Time-maximum total precipitation rate | kg m**-2 s**-1 | 6h | max |
| 228225 | mntpr6 | Minimum total precipitation rate in the last 6 hours | kg m**-2 s**-1 | 238055 | min_tprate | Time-minimum total precipitation rate | kg m**-2 s**-1 | 6h | min |
Maximum CAPE and CAPE Shear
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | Old units | New paramId | New shortName | New name | New units | timespan | stepType |
|---|---|---|---|---|---|---|---|---|---|
| 228035 | mxcape6 | Maximum CAPE in the last 6 hours | J kg**-1 | 237287 | max_cape | Time-maximum convective available potential energy | J kg**-1 | 6h | max |
| 228036 | mxcapes6 | Maximum CAPES in the last 6 hours | m**2 s**-2 | 237321 | max_capes | Time-maximum convective available potential energy shear | m**2 s**-2 | 6h | max |
Mean total lightning flash density
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | Old units | New paramId | New shortName | New name | units | timespan | stepType |
|---|---|---|---|---|---|---|---|---|---|
| 228051 | litota1 | Averaged total lightning flash density in the last hour | km**-2 day**-1 | 235326 | avg_litoti | Time-mean total lightning flash density | km**-2 day**-1 | 1h/3h/6h | avg |
| 228057 | litota3 | Averaged total lightning flash density in the last 3 hours | km**-2 day**-1 | 235326 | avg_litoti | Time-mean total lightning flash density | km**-2 day**-1 | 3h | avg |
| 228058 | litota6 | Averaged total lightning flash density in the last 6 hours | km**-2 day**-1 | 235326 | avg_litoti | Time-mean total lightning flash density | km**-2 day**-1 | 6h | avg |
Most severe and most frequent precipitation type
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | New paramId | New shortName | New name | timespan | stepType |
|---|---|---|---|---|---|---|---|
| 260318 | ptype_sev1h | Precipitation type (most severe) in the last 1 hours | 260682 | sev_ptype | Time-severity precipitation type | 1h | severity |
| 260319 | ptype_sev3h | Precipitation type (most severe) in the last 3 hours | 260682 | sev_ptype | Time-severity precipitation type | 3h | severity |
| 260338 | ptype_sev6h | Precipitation type (most severe) in the last 6 hours | 260682 | sev_ptype | Time-severity precipitation type | 6h | severity |
| 260320 | ptype_freq1h | Precipitation type (most frequent) in the last 1 hours | 260683 | freq_ptype | Time-mode precipitation type | 1h | mode |
| 260321 | ptype_freq3h | Precipitation type (most frequent) in the last 3 hours | 260683 | freq_ptype | Time-mode precipitation type | 3h | mode |
| 260339 | ptype_freq6h | Precipitation type (most frequent) in the last 6 hours | 260683 | freq_ptype | Time-mode precipitation type | 6h | mode |
Ocean model output
The paramId's and shortNames for the following output from the ocean model have changed. In addition:
- the unit of Sea surface practical salinity and Average sea water practical salinity in the upper 300 m has changed from psu to g/kg;
- the unit of the Average sea water potential temperature in the upper 300m has changed from degrees Celsius to Kelvin.
Key values that are different are highlighted in bold.
| Old paramId | Old shortName | Old name | Old units | New paramId | New shortName | New name | New units |
|---|---|---|---|---|---|---|---|
| 151130 | so | Sea water practical salinity | psu | 262100 | sos | Sea surface practical salinity | g kg**-1 |
| 151131 | ocu | Eastward surface sea water velocity | m s**-1 | 262140 | sve | Eastward surface sea water velocity | m s**-1 |
| 151132 | ocv | Northward surface sea water velocity | m s**-1 | 262139 | svn | Northward surface sea water velocity | m s**-1 |
| 151145 | zos | Sea surface height | m | 262124 | zos | Sea surface height | m |
| 151148 | mld | Mixed layer depth | m | 3067 | mld | Mixed layer depth | m |
| 151163 | t20d | Depth of 20C isotherm | m | 262104 | t20d | Depth of 20 C isotherm | m |
| 151164 | tav300 | Average potential temperature in the upper 300m | degrees C | 262144 | pt300m | Average sea water potential temperature in the upper 300m | K |
| 151175 | sav300 | Average sea water practical salinity in the upper 300m | psu | 262118 | sc300m | Average sea water practical salinity in the upper 300 m | g kg**-1 |
| 174098 | sithick | Sea-ice thickness | m | 262000 | sithick | Sea ice thickness | m |
Parameters provided with WMO units
For some parameters, ECMWF has been providing values in units which are not the official WMO units. The static sample dataset also includes examples of the same parameters but with values provided in the official WMO units. These parameters are provided in files identified by the ECMWF paramId and shortName in the file name but with the additional tag "_wmo_units". For example, the total precipitation parameter, which ECMWF has been providing in units of "metres" (m), is also provided in units of kg/m2 in a file named 228_od_oper_fc_sfc_tp_2024_0001_regular_ll_wmo_units.grib2.
Parameters encoded by ECMWF in units of metres or metres of water equivalent
The following parameters that have been encoded in units of metres or metres of water equivalent, such as total precipitation, are also provided in the standard WMO unit of kg/m2.
| class / stream / type / levtype | Parameters encoded with ECMWF units | Parameters encoded with WMO units | ||||||
|---|---|---|---|---|---|---|---|---|
| paramId | shortName | name | units | paramId | shortName | name | units | |
| 141 | sd | Snow depth | m of water equivalent | 3066 | sde | Snow depth | m |
| 142 | lsp | Large-scale precipitation | m | 3062 | lsp | Large-scale precipitation | kg m**-2 |
| 143 | cp | Convective precipitation | m | 228143 | cp | Convective precipitation | kg m**-2 |
| 144 | sf | Snowfall | m of water equivalent | 260025 | asnow | Total snowfall | m |
| 182 | e | Evaporation | 260259 | eva | Evaporation | kg m**-2 | |
| 198 | src | Skin reservoir content | m of water equivalent | 160198 | srcon | Skin reservoir content | kg m**-2 |
| 205 | ro | Runoff | m | 231002 | rowe | Runoff water equivalent (surface plus subsurface) | kg m**-2 |
| 228216 | fzra | Accumulated freezing rain | m | 231001 | fzrawe | Accumulated freezing rain water equivalent | kg m**-2 |
| 228251 | pev | Potential evaporation | m | 231005 | peva | Potential evaporation | kg m**-2 |
| 228 | tp | Total precipitation | m | 228228 | tp | Total precipitation | kg m**-2 |
| 44 | es | Snow evaporation | m of water equivalent | 231003 | eswe | Snow evaporation water equivalent | kg m**-2 |
| 45 | smlt | Snowmelt | m of water equivalent | 3099 | snom | Snowmelt | kg m**-2 |
| 8 | sro | Surface runoff | m | 231010 | ssurfro | Surface runoff | kg m**-2 |
| 9 | ssro | Sub-surface runoff | m | 231012 | ssurfro | Sub-surface runoff | kg m**-2 |
Parameters encoded by ECMWF as fractional values between 0 and 1
The following parameters that have been encoded by ECMWF in fractional units with values between 0 and 1, such as the cloud cover and albedo parameters, are also provided in the standard WMO unit percentage (%).
| class / stream / type / levtype | Parameters encoded with ECMWF units | Parameters encoded with WMO units | ||||||
|---|---|---|---|---|---|---|---|---|
| paramId | shortName | name | units | paramId | shortName | name | units | |
| 164 | tcc | Total cloud cover | (0 - 1) | 228164 | tcc | Total cloud cover | % |
| 186 | lcc | Low cloud cover | (0 - 1) | 3073 | lcc | Low cloud cover | % |
| 187 | mcc | Medium cloud cover | (0 - 1) | 3074 | mcc | Medium cloud cover | % |
| 188 | hcc | High cloud cover | (0 - 1) | 3075 | hcc | High cloud cover | % |
| 15 | aluvp | UV visible albedo for direct radiation (climatological) | (0 - 1) | 210199 | aluvp_p | UV visible albedo for direct radiation (climatological) | % |
| 16 | aluvd | UV visible albedo for diffuse radiation (climatological) | (0 - 1) | 210198 | aluvd_p | UV visible albedo for diffuse radiation (climatological) | % |
| 17 | alnip | Near IR albedo for direct radiation (climatological) | (0 - 1) | 210261 | alnip_p | Near IR albedo for direct radiation (climatological) | % |
| 18 | alnid | Near IR albedo for diffuse radiation (climatological) | (0 - 1) | 210260 | alnid_p | Near IR albedo for diffuse radiation (climatological) | % |
| 32 | asn | Snow albedo | (0 - 1) | 228032 | asn | Snow albedo | % |
| 174 | al | Albedo (climatological) | (0 - 1) | 260509 | al | Forecast albedo | % |
| 243 | fal | Forecast albedo | (0 - 1) | 260509 | al | Forecast albedo | % |
| 210186 | aluvpi | UV visible albedo for direct radiation, isotropic component (climatological) | (0 - 1) | 210201 | aluvpi_p | UV visible albedo for direct radiation, isotropic component (climatological) | % |
| 210187 | aluvpv | UV visible albedo for direct radiation, volumetric component (climatological) | (0 - 1) | 210202 | aluvpv_p | UV visible albedo for direct radiation, volumetric component (climatological) | % |
| 210188 | aluvpg | UV visible albedo for direct radiation, geometric component (climatological) | (0 - 1) | 210200 | aluvpg_p | UV visible albedo for direct radiation, geometric component (climatological) | % |
| 210189 | alnipi | Near IR albedo for direct radiation, isotropic component (climatological) | (0 - 1) | 210263 | alnipi_p | Near IR albedo for direct radiation, isotropic component (climatological) | % |
| 210190 | alnipv | Near IR albedo for direct radiation, volumetric component (climatological) | (0 - 1) | 210264 | alnipv_p | Near IR albedo for direct radiation, volumetric component (climatological) | % |
| 210191 | alnipg | Near IR albedo for direct radiation, geometric component (climatological) | (0 - 1) | 210262 | alnipg_p | Near IR albedo for direct radiation, geometric component (climatological) | % |
Total column ozone
Total column ozone which has been encoded by ECMWF with values in units of kg/m2 is also provided in Dobson Units.
| class / stream / type / levtype | Parameters encoded with ECMWF units | Parameters encoded with WMO units | ||||||
|---|---|---|---|---|---|---|---|---|
| paramId | shortName | name | units | paramId | shortName | name | units | |
| 206 | tco3 | Total column ozone | kg m**-2 | 260132 | tcioz | Total column integrated ozone | Dobson Units (DU) |